BHT, butylated hydroxytoluene, has been used for decades as a food antioxidant additive for preservative purposes (as well as a material for experimental studies of life extension in animals). Many people, however, stay away from anything containing BHT because of a concern about its synthetic nature. Recently, however, a group of researchers discovered that four freshwater phytoplankton, including a green alga and three cyanobacteria, produce BHT as an antioxidant:1 the researchers found that the quantity of cellular BHT displayed a positive correlation with the antioxidant activity of the tested species. The scientists suggested that “these species constitute a potential source for producing natural BHT.” True, but a molecule of natural BHT is the same as a molecule of synthetic BHT, so it really doesn’t matter who produced it, man or phytoplankton.

Reference

Babu and Wu. Production of natural butylated hydroxytoluene as an antioxidant by freshwater phytoplankton. J Phycol 44:1447-54 (2008).